Slack-adjuster for railway-brakes.



P. D. WARD. SLACK ADJUSTER FOR RAILWAY BRAKES.

APPLICATION FILED JAN.9,1914.

Patented Oct. 6, 1914.

2 SHEETS-SHEET 1.

inventor:

F. D. WARD.

SLACK ADJUSTER POE RAILWAY BRAKES.

APPLICATION FILED JAN. 9, 1914.

1 1 1 2,504. Patented oat/6, 1914.

2 SHEETSSHEET 2.

Inventor: by 4WD. W 1

FRANK D. WARD, OF NEW YORK, N. Y.

SLACK ADJUSTER FOR RAILWAY-BRAKES.

Specification of Letters Patent.

Patented (Dot. 8, 19143:.

Application filed January 9', 1914. Serial No. 811,157.

To all whom it may concern:

Be it known that I, FRANK D. 'WARD, a citizen of the United States, residing in the borough of Manhattan of the city of New York, in the State of New York, have invented certain ne w, aniiLuseful Improvements in Slack-Adjusters for Railway-Brakes, of which the following'is a specification,reference being had to the accompanying drawings, forming a part hereof.

This invention relates generally to slack adjusters of the type shown in an application filed by the present applicant on July 28, 1913, Serial No. 7 81, l89, in which is employed a rack bar movable longitudinally in one direction to take up the slack in the brake rigging-after excess travel of the pull rod by reason of such slack. The present invention seeks to improve the devices of said prior application and is concerned particularly with the provision of means for locking the rack .bar against accidental movement in either direction. The inertia of the rack bar and its associated parts under sudden impulses, such as are received when two or more cars are coupled together or when a car equipped with the slack ad juster devices is started or stopped, is considerable, and indeed may cause the bodily movement of the rack bar from its normal position of rest, thereby taking up prematurely the needed slack in the brake rlgging. By-the resent invention the rack bar is held against movement in one 'direction under such external forces by the holding dog and in the other direction by means of an improved pawl which may not only serve to hold the rack bar against such accidental movement but in accordance with the illustrated embodiment constitutes the take-up pawl and as such performs-its usual function.

The invention will be described more par ticularly with reference to the accompanying drawings, in which 4 Figure 1 is a fragmentary view in side elevation of part of the Wheels and truck of a railway car equipped with the improved slack adjusten. Fig. 2 is a view on an enlarged scale, in side elevation, of the improved adjuster, part of the casing being removed to show the operative parts of the ad juster and the brakes being-applied so that the take-up rod is partially retracted from its position within its casing. v Fig. 3 is a view taken on the plane indicated by the 11 18 3-3 of FigPQ and looking inthe direction of the arrows.

The construction and operation of so much of the brake system as is necessary for a clear understanding of the present improvements will be pointed out before the latter are described in detail, the present system, for the sake of convenience being identical with that illustrated and described in the co-pending application above referred to, although it will be understood as this description proceeds that the present invention is not to be limited in its application to a system of the preciseform.

In Fig. 1 is illustrated, in a somewhat conventional manner,-the application of the slack adjuster system to a car. The brake shoes a, a are shown as suspended by links b, b from the car truck (not illustrated) and controlled in their movement by a live lever" c and a dead lever 03 respectively, these operating levers being interconnected adjacent their lower ends by the usual bottom rod e. The upper end of the dead lever cl, which constitutes the adjustable fulcrum of the brake rigging, is connected through a suitable chain cZ with a rack bar d slidably disposed within a suitable casing f suspended from the-car truck as-through a clamp g and links h. The rack bar (2?, which may be of substantially the same form as that illustrated in said co-pending application, has formedthereon a series of teeth. d? with which cooperates a spring-pressed holding dog 2', and a second series of teeth a, disposed at any desired and'practicable angle with respect to the first named series of teeth. It will now appear that so long as the dog '5 is in engagement with the teeth a? of the rack bar (Z movement thereof to the right, as viewed in Fig. 1, either by manipulation or accidentally, as through the influence of external shocks, cannot occur.

Theinner side walls of the inclosing casing f are formed to receive a sliding take-up rod is operatively connected through a chain ldwiththe upper end of the live lever 0 and the usual pull rod Z, the latter being connected to a suitable source of power. The inner end of the take-up rod is may be supported and guided in'its movement y a pin 10 the ends of which are disposed within suitable longitudinal grooves f formed in the oppositeside walls of the supporting casing. Pivotally mounted on the pin 10 within the casing is the improved pawl m roe which may have in addition to its pivotal movement a bodily movement With respect to the pin 70 through the inclined slot or Within which the pin rests. The toe m of the pawl mcooperates With the teeth (Z' of the rack bar (F, the toe being provided "with an integral stud m the end or which rests soinewhht loosely in guide grooves or shoul ders f also formed in the inner side Walls or me supporting casing f. The inner ends about l a suitable spiral sp' n disposed within the casing f and int vLposed opera tively be tween one end Wall of the ca ir and the pawl m so as to l to force the latter ii nvardly with respect to the pin 55 and maintain said pin in the lower end of the slot m, as indicated in i ll lines, in

The inner end of the sprin cit preferably abuts inst a Washer 72/ which in turn, abuts aeainst the rear-face of the pawl m this rear race being preferabi curved so to facilitate its movement along" the Washera in the manner to he described hereinafter: The description thus far "ven applies in antial respects to 'tliE brake svst n in the BO-POllCllIlg l catiosave for the slot m the pawl m believed that such dos ription to enable the application provernents to he l tood. 1'3

1e panm preferaoi has in 1e prese lhodirnent its tori l UZY'EF lace red with carved 2 am sur m, ch ngages an inclined or f i orinod on the inner end mail of the cas ing f, when the pawl m is force as vised in Fig under the influence oi the 21111 face f in its be omitted ent' parting IlOlIl the scope of the invention althou g'h it is necessary that there le provided a suitahle abutting surface, such shouh der to lock the pawl m in o tive egagenicnt with the racli bar as will ater appear.

i accidental movement to the lei in Flo 2),

unti

:Q t (as viewed i m e a: 11 1111:; Iorces t the lower part of the rear face of the pawl is termed a second toe or lug m and the brakes are released, the WW1 m is held at the extreme left end of as indicated in dotted lines in. a, stud m resting adjacent the ends of the shoulders f and the pin k course, re maining in the grooves f. in reachin this extreme position the tension of the talte-np spring or is sullicient to rock the pawl or bodily on its cam itace RH/1' along the cam lace f so as to throw the body of the pawl m downwardly until the pin 70 rests in the up per end of the slot m. The i and size of the parts are such that when the pawl m is in its extreme downward position the too or lug m engages eii i ectively the beveled face of one of the teeth (3* of the ack car (i so as to prevent the accidental i re rement of the rack bar to the left (as viciveu in Fig The locking engagement of e pawl m with the rack bar indeed becomes a positive one in that any tendency ol the rack bar to move to the lei; (as viewed in m 5; serves merely to wedge the pawl on between the shoulder f and eeth a with which the lug m or gages, 1e sprin' 9t assisting this action t will h evitleno The operation oi? the lillO'OYQtl devic s posite direction is prevented thecngiagcn'ient of the dog 2' v teeth d of the raclr her (15 tion of the brakes the pawl an 1 Ward the right viewed in and the cam face m is inoved from under the shoulder f in its locked positio the cam face 7, under the in spring 1?, in the manner above descr disengages the lug m from thereby permitting the rack l inoved to the left viewed ii case there is slack to be taken u subsequent release of the brakes The rack bar a, as illustrated, may he rotatable in the copending referred to, being provided Wit to facilitate manual oneration, t rotating the rack bill lieing to move d and (5 out of engagement and lug m respectively and pen it bar to he slid longitudinally to re ase coinpletely the brake rigging and roit neces sary adjustments or repairs to made.

As suggested hereinbefore modifications 113 3 in the details of construction of the brake system and the arrangement of its may be made Without departing; spirit of the present invention proved devices being equally ap serviceable in connection with other forms of brake rigging functioning in substantially the same manner.

it claim as my invention:

IL The combination of a hotly, a truclr 13-0 I on the supporting means and cooperating with the pawl to hold the same out of engagement with the teeth of the rack bar during normal travel of the pull rod and permitting engagement of the pawl with the teeth of the rack bar upon excess travel of the pull rod and means to force the pawl into positive locking engagement with the teeth to prevent movement of the rack bar in the opposite direction after thebrakes have been released.

2. The combination of a car body, a truck, a brake system comprising a live lever and a dead lever and an automatic take-up device including supporting means mounted on the car body and comprising a rack bar and a take-up rod, a pawl pivotally mounted on the take-up rod and connecting the same operatively with the rack bar, the supporting means and the pawl being provided with cooperating cam surfaces to force the pawl into locking engagement with the rack bar to hold the same against movement in one direction when the brakes are released and a spring-pressed holding dog mounted on said supporting means and engaging the rack bar to prevent positively movement thereof in the opposite direction.

3. The combination of a car body, a truck, a brake system comprising a live lever and a dead lever, a casing supported on the car body, an automatic take=up device supported in said casing and including two rods oper atively connected to the dead lever and to the pull'rod respectively, a pawl supported pivotally within said casing on the inner end of the pull rod and operative upon excess travel of the pull rod to connect said two first named rods, guide shoulders formed on the inner side walls of the casing and cooperating with the toe of said pawl to determine its position, the body of said pawl being provided with a slot to receive the pivot pin of the pawl, a spring in operative engagement with the body of the pawl to hold the same normally out of engagement with the rack bar and cooperating cams formed on the inner wall of the casing and on the body of the pawl to force the latter into locking engagement with the rack bar after the brakes have been released.

This specification signed and witnessed this eighth day of January A. D. 1914.

FRANK D. WARD.

Signed in the presence of ELLA J. KRUGER, Wonrnmeron CAMPBELL. 

